Connecting external power supply to MCU

Thread Starter

King2

Joined Jul 17, 2022
80
Will there be any damage to microcontroller's like AVR, PIC, ARM if a high current power supply is connected to it?

Suppose I have connected a 5 volt/3 amp DC power supply to the micro controller , can it damage the microcontroller?
 

Jerry-Hat-Trick

Joined Aug 31, 2022
175
A 5V power supply should be able to hold a steady 5V ouput for any current drawn from it, up to its stated current limit - in your case 3A. Anything connected to the supply will just take the current it needs.
 

Dodgydave

Joined Jun 22, 2012
10,520
Any psu won't force out the current, it is up to the load that decides how much current is needed , so your micro will be ok as long as the psu is capable of the demand.
 

nsaspook

Joined Aug 27, 2009
10,427
The current circulation in the circuit is a indicator (not the source) of the power drawn by the circuit. Microcontroller's are usually low power devices so their normal current path is minimal. In the 'old' days we would bolt 5V 50A+ power supplies for TTL digital to circuits boards in a card cage. The main issue with high current power supplies directly connected to small components on a PCB is fusing/current limiting for electrical safety. One slip with a scope or meter probe could and has burned traces and wiring to a crisp from the short to the power bus without the power supply blinking an eye (short circuit current below the overcurrent protection mechanism) due to the current draw.
https://iopscience.iop.org/article/10.1088/1742-6596/1634/1/012047/pdf
1663427260690.png1663427274804.png
 

Thread Starter

King2

Joined Jul 17, 2022
80
Any psu won't force out the current, it is up to the load that decides how much current is needed , so your micro will be ok as long as the psu is capable of the demand.
So we have to find out how much current is required for each load

The main issue with high current power supplies directly connected to small components on a PCB is fusing/current limiting for electrical safety.
Sometimes the leads of the multimeter may connect to the two GPIO pins of the microcontroller while working

If two GPIO pins of the micro controller are shorted by mistake, will the whole micro controller be damaged?
 

nsaspook

Joined Aug 27, 2009
10,427
If two GPIO pins of the micro controller are shorted by mistake, will the whole micro controller be damaged?

Shorted to what?
Unlikely if they were plain-Jane GPIO pins shorted just to each other.
 

Reloadron

Joined Jan 15, 2015
6,991
Will there be any damage to microcontroller's like AVR, PIC, ARM if a high current power supply is connected to it?

Suppose I have connected a 5 volt/3 amp DC power supply to the micro controller , can it damage the microcontroller?
If you connect a 5.0 volt 3.0 amp power supply to a micro-controller designed to operate on 5.0 volts the micro-controller will only draw its rated current. Now if you connect that same 5.0 volt supply for a uC designed to run on 3.3 volts for example you can expect smoke and will destroy your uC. As to load current draw? The load will only draw its rated current as long as your supply can provide it. For example connecting a 5.0 volt 3.0 amp supply to a 5.0 volt 5.0 amp load is not going to work. Just remember to make sure your supply voltage never exceeds the load rated voltage.

Ron
 
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